Not entirely true; think about the moment (i.e. the force applied on the disc by the calliper to the centre point). It's like a lever; the further away you have it from that centre point, the more force can be put on it (a higher moment)... so better braking.Bigger discs dont mean better braking, just better cooling as your spreading the friction over a larger area. So all this prevents is brake fade.
To get better braking you need better calipers, ie more pots.
from experiance bigger discs give me better braking. more pots just applies the fore more equal across the pad. most 4 pots are also alot lighter than cast iron single pots so give a lower unsprung mass.Bigger discs dont mean better braking, just better cooling as your spreading the friction over a larger area. So all this prevents is brake fade.
To get better braking you need better calipers, ie more pots.
why do you need to redrill hub? can you not just redrill disc to suit hub stud pattern?You can use Almera hubs N15 and stub axles with z32 4 pots and disc you will need adjustable length track rod ends and have to re-drill the discs and hubs and take 4mm off the disc diameter cheaper than a lot of conversions and easier than making brackets.